T  P 


UC-NRLF 


SMI 


LIBRARY 


UNIVERSITY  OF  CALIFORNIA. 


Class 


Fuel  Economy 

In  Sugar  Factories 


SAMUEL  L.  JODIDI,  Ph.  D. 


Reprinted  from  the 

AMERICAN    SUGAR   INDUSTRY 
and  BEET  SUGAR  GAZETTE,  19O5 


PRICE    50   CENTS 


BEET  SUGAR  GAZETTE  COMPANY 

Publishers 
Chicago.  Illinois,  U.  S.  A. 


OF  THE 

UNIVERSITY 

OF 


FUEL    ECONOMY    IN    SUGAR    FACTORIES. 


BY    SAMI'KL    L.    JODIDI,    PH.    D. 


A  sugar  factory  works  rationally  not  merely  when  it 
produces  good  sugar  and  obtains  a  high  yield  per  100 
parts  of  beets,  but  also  when  it  works  economically,  i.  e., 
if  the  expenses  for  fuel,  employes,  limestone,  etc.,  are 
minimized.  Among  these  expenses  those  for  fuel  are 
doubtless  the  most  considerable,  and,  although  science  and 
technics  give  sufficient  means  to  control  the  work  in  the 
boiler  house  and  to  put  it  upon  a  rational  basis,  this  phase 
is  not  seldom  neglected  during  the  campaign,  but  this 
causes  a  waste  of  fuel. 

In  the  following  are  the  results  obtained  during  the 
last  campaign  in  a  sugar  factory  in  this  country,  of  600 
tons  daily  capacity.  In  its  boiler  house  were  altogether 
fourteen  boilers :  Eight  high-pressure  boilers  with  105-125 
pounds  steam  pressure  for  engines,  and  six  low-pressure 
boilers  with  45-60  pounds  steam  pressure  for  boiling  pur- 
poses. One  boiler  of  the  high-pressure  line  had  also 
connection  with  the  low-pressure  line  and  was  able  to 
produce  steam  of  low  pressure  in  case  the  factory  needed 
more  boiling  steam.  All  boilers  of  both  lines  had  the  same 
heating  surface  of  about  150  square  meters  each.  The 
grates  were  also  of  the  same  size,  namely  6'  X  6'  =  36 
square  feet.  The  chimney  draught  observed  was  i"  water 

I «6085 


level.  Pennsylvania  soft  coal,  the  analysis  of  which  will 
be  given  later,  was  used  as  fuel. 

It  is  agreed  that  no  one  can  produce  sugar  in  the  fac- 
tory, and  the  problem  is  considered  to  be  solved  satisfac- 
torily when  the  sugar  is  extracted  from  the  beets  in  such 
a  manner  that  the  losses  are  as  small  as  possible.  The 
same  may  be  said  with  reference  to  the  fuel.  The  heat 
cannot  be  produced  in  a  boiler  house.  But  when  the 
energy — which  was  stored  up  in  the  plants  by  the  sun 
some  centuries  or  millenniums  ago,  and  has  remained  in 
the  fuel  built  up  from  the  plants  of  that  time  by  their 
decomposition — may  be  extracted  in  form  of  heat,  as 
fully  as  possible,  and  the  losses  minimized,  it  is  evident 
that  such  a  boiler  house  works  rationally. 

In  order  to  determine  what  "rational  work"  in  a  boiler 
house  means,  we  ought  to  answer,  above  everything  else, 
the  question :  What  percentage  of  carbon  dioxide  is  it 
possible  to  obtain,  theoretically,  in  the  burning  of  coal  in 
the  air?  This  is  necessary  because  it  will  enable  us  to 
ascertain  the  figures  we  must  try  to  attain.  Now,  accord- 
ing to  Avogadro's  law  of  1811,  in  equal  volumes  of  any 
gases  an  equal  number  of  molecules  is  contained,  or  a 
molecule  of  any  gas  is  always  the  same  volume.  The 
complete  combustion  of  carbon  in  oxygen  takes  place 
according  to  the  equation  C  +  O*  —  CO  (equation  I), 
in  which  COz  =  2  volumes  (liters  or  cubic  meters,  etc.) 
of  carbon  dioxide  and  the  molecule  O»  =  2  volumes 
(liters  or  cubic  meters,  etc.)  of  oxygen,  according  to  the 
above-mentioned  law. 

In  the  burning  of  carbon  with  two  or  any  volumes  of 
oxygen  result  two  or  the  same  volumes  of  carbonic  acid. 
However,  the  air  consists  not  only  of  oxygen,  but  also 
of  79.08  volumes  of  nitrogen,  which  does  not  take  part 
in  the  process  of  combustion.  So  that  20.92  volumes  of 


oxygen   contain   79.08   volumes   of   nitrogen ;   then   two 

79.08 
volumes  of  oxygen  contain  -     -  X  2  =  7.56  volumes  of 

20.92 

nitrogen.  Adding  this  to  both  parts  of  the  equation  I 
we  have :  0  +  02  +  7.56  volumes  N  =  CO  +  7.56  vol- 
umes N  =  9.56  volumes  of  gas  of  combustion  (equation 
II),  in  which  N  =  nitrogen.  This  equation  expresses 
that  in  the  burning  of  carbon  in  an  amount  of  air  neces- 
sary for  its  complete  combustion,  there  results  a  gas 
consisting  of  2  volumes  of  carbon  dioxide  and  7.56  vol- 
umes of  nitrogen.  Expressed  in  percentage  ratio  we 
find: 

9.56  vols.  of  combustion  gas  contain  2  vols.  of  carbon  dioxide. 
100.00  vols.  of  combustion  gas  contain  x  vols.  of  carbon  dioxide. 

2X  ioo 
x  :  2  —  ico  :Q.56 ;  x=  =20.92  per  cent  of  carbon  dioxide. 

9.56 

Further : 

9.56  vols.  of  combustion  gas  contain  7.56  vols.  of  nitrogen, 
loo.oo  vols.  of  combustion  gas  contain       y  vols.  of  nitrogen. 

7.56  X  ioo 
y  :  7.56  =  ioo :  9.56 ;   y  =  —  =  79.08  per  cent  of  nitrogen. 

9.56 
In  words :   If  carbon  would  burn  completely  to  carbon 

dioxide  in  an  amount  of  air  that  is  theoretically  just  suffi- 
cient, then  a  gas  would  result  containing  79.08  per  cent 
of  nitrogen  and  20.92  per  cent  carbonic  acid,  i.  e.,  con- 
taining just  the  same  per  cent  of  nitrogen  as  our  atmos- 
phere, and  as  great  a  percentage  of  carbonic  acid  as  the 
atmosphere  contains  of  oxygen.  Thus  20.92  is  the  high- 
est .percentage  of  carbon  dioxide  which  is  theoretically 
obtainable  in  the  perfect  combustion  of  carbon  in  the  air ; 
and  these  figures  we  ought  to  try  to  attain  in  our  boiler 
houses,  or  to  approximate  them  as  nearly  as  possible. 

However,  in  practice  we  are  never  able  to  furnish  a 
combustion  gas  with  such  high  contents  of  carbon  dioxide. 
If  for  the  combustion  of  coal  the  exact  amount  of  air 


that  is  required  by  the  theory  should  be  used,  the  result- 
ing gas  would  contain  carbon  monoxide  as  well  as  car- 
bon dioxide,  i.  e.,  the  combustion  would  not  be  complete. 
Experience  has  shown  that  the  most  perfect  combus- 
tion takes  place  if  from  one  and  a  half  to  two  times  the 
amount  of  air  that  the  theory  requires  be  employed.  Ac- 
cordingly, changing  equation  II,  we  have  :  C  +  Oa  -f-  O  -}- 
7.56  volumes  NX  i/4  —  CO?  ~|-  O  +  7- 56  volumes  N  X 
iy2  =  14.34  volumes  of  combustion  gas  (equation  III), 
in  which  O  =  i  volume  (liter  or  cubic  meter)  of  oxygen. 
Expressed  in  percentage  we  have : 

14.34  vols.  of  combustion  gas  contain  2  vols.  of  carbonic  acid. 
100        vols.  of  combustion  gas  contain  z  vols.  of  carbonic  acid. 

2  X  100 
z:  2=100:  14.34;  z==  i==I3-95  Per  cent  °f  carbonic  acid. 

14-34 
In  other  words :    If  for  combustion  of  carbon,  one  and 

a  half  times  as  many  volumes  of  air  be  employed,  as  the 
theory  requires,  the  resulting  gas  would  contain  13.95 
per  cent  of  carbonic  acid. 

In  a  similar  manner  we  find :  C  +  O*  +  O  +  7.56  vol- 
umes N  X  2  =  CO  +  O  -f  7.56  volumes  N  X  2  —  19.12 
volumes  of  combustion  gas  (equation  IV).  This,  ex- 
pressed in  percentage,  gives: 

19.12  vols.  of  combustion  gas  contain  2  vols.  of  carbonic  acid, 
loo        vols.  of  combustion  gas  contain  u  vols.  of  carbonic  acid. 

2  X  100 
u:  2=  100:  19.12;  u=  =  10.46  per  cent  of  carbonic  acid. 

19.12 

In  words :  If  for  combustion  of  carbon,  two  times  as 
many  volumes  of  air  be  employed  as  the  theory  requires, 
the  resulting  gas  would  contain  10.46  per  cent  of  carbonic 
acid.  It  follows,  from  equations  II,  III  and  IV,  that  as 
long  as  a  combustion  gas  contains  from  10  to  21  per  cent 
of  carbonic  acid — to  be  exact,  from  10:46  to  20.92 — the 
combustion  must  be  considered  as  a  favorable  one,  and 
the  nearer  to  20.92  the  better. 


But  on  the  other  hand:  How  many  pounds  (kilograms 
or  tons)  of  air  are  necessary  for  the  complete  combus- 
tion of  i  pound  (kilogram  or  ton)  of  carbon?  And 
further,  how  many  pounds  of  air  per  pound  of  carbon 
were  actually  used  in  the  sugar  factory  in  question  ? 

Equation  I  expressed  by  weight  gives :  C  -|-  O  =  CO. 
Since  carbon  (C)  and  oxygen  (O)  have  the  atomic 
weights  12  and  16  respectively,  this  equation  means  that 
in  order  to  burn  to  carbonic  acid, 

12  pounds  of  carbon"  need  32  pounds  of  oxygen,  or  I   pound  of 

32 
carbon   needs  —  pounds  of  oxygen. 

12 
Now,  we  know  that  our  atmosphere  consists  not  merely 

of  oxygen,  but  also  of  nitrogen,  namely,  100  parts  of  the 
atmosphere  contain  23.1  per  cent  by  weight  of  oxygen 
and  76.9  per  cent  by  weight  of  nitrogen.  In  consequence, 

32        100 
i  pound  of  carbon  needs  theoretically  -  ——  11.54 

12       23.1 
pounds  of  air  in  order  to  burn  to  carbon  dioxide. 

The  figures  11.54  pounds  of  air  we  have  calculated 
for  i  pound  of  carbon.  But  in  the  sugar  factories,  coal, 
as  ordinarily  used,  contains,  besides  carbon,  also  moisture, 
ash,  sulphur,  etc.  It  is  evident  that  i  pound  of  coal  needs 
for  its  combustion  a  different  quantity  of  air  from  carbon. 
This  we  now  proceed  to  calculate. 

In  the  sugar  factory  in  question,  in  the  last  campaign, 
Pennsylvania  soft  coal,  the  composition  of  which  is  given 
below,  was  used : 

Water  (moisture).  Ash.  Sulphur.  Carbon.       *Hydrogen. 

1.44  9-14  0.57  78.10  4.8 

Of  these  constituents  only  carbon,  hydrogen  and  sul- 
phur unite  with  oxygen.  According  to  this  analysis,  in 
100  pounds  of  coal  are  contained  78.10  pounds  of  carbon, 

* [(Oxyg en  -f-  Nitrogen)   5.95  by  difference.] 
5 


4.8  pounds  of  hydrogen  and  0.57  pound  of  sulphur.  As 
we  have  already  learned  above,  i  pound  of  carbon  needs 
for  its  combustion  11.54  pounds  of  air;  consequently 
78.10  pounds  of  carbon  need  11.54X78.10  =  901.27 
pounds  of  air.  The  second  constituent,  hydrogen,  unites 
with  oxygen  according  to  the  equation  Hz  -)-  O  =  Had). 
Since  hydrogen  has  the  atomic  weight  I,  this  equation 
means  that  2  pounds  of  hydrogen  (H)  need  for  their 
combustion  16  pounds  of  oxygen  (O),  or  i  pound  of 
hydrogen  needs  8  pounds  of  oxygen.  In  order  to  get 
the  quantity  of  air  necessary  for  i  pound  of  hydrogen,  we 

100 
ought  to  multiply  the  amount  of  oxygen  by  -       -   (see 

23.1 
page  5),  i.  e., 

100 

i  pound  of  hydrogen  uses  8  X =  34-63  pounds  of  air.  Con- 

23.1 

sequently,  4.8  pounds  of  hydrogen  use  34.63  X  4.8=  166.22  pounds 
of  air. 

Finally,  the  third  constituent,  sulphur,  unites  with 
oxygen  according  to  the  equation  S  +  O2  =  SO,  and,  as 
sulphur  (S)  has  the  atomic  weight  32,  this  equation 
means  that,  for  their  combustion. 

32  pounds  of  sulphur  need  32  pounds  of  oxygen,  or  i  pound 

100 

of  sulphur  needs  i  pound    of  oxygen,  corresponding  to  i  X 

23.1 
—  4-33  pounds  of  air. 

Consequently,  0.57  pound  of  sulphur  uses  4.33  X  0.57  =  2.47 
pounds  of  air. 

Adding  the  results  calculated  for  carbon,  hydrogen  and 
sulphur,  we  find  :  901.27  +  166.22  +  2.47  —  1,069.96. 
Thus  we  have  found  that,  for  their  combustion, 

loo  pounds  of  our  coal  theoretically  need  1,069.96  pounds  of 
air,  or  i  pound  of  our  coal  theoretically  needs  10.70  pounds  of 
air. 

Consequently,  10.70  pounds  of  air  are  the  least  amount 


of  air  necessary  for  the  combustion  of  I  pound  of  our 
coal.  However,  modern  technics  has  as  yet  no  means 
fully  to  utilize  in  one  run  all  the  oxygen  contained  in  the 
air.  This  is  the  reason  that  in  practice  we  must  use  from 
150  to  200  per  cent  of  the  air  theoretically  calculated. 
The  ratio  of  the  air  theoretically  necessary  for  I  pound  of 

10.70 
coal  to  that  of  i  pound  of  carbon  is  then  -       — .     This 

H-54 
ratio  we  shall  use  in  the  succeeding  pages. 

Let  us  see  how  much  air  was  used  in  the  boiler  house 
of  the  sugar  factory  in  question.  The  examinations  of 
the  flue  gases  *  made  in  the  period  between  the  4th  and 
the  1 5th  of  November,  1904,  gave  the  following  results: 

The  composition  of  the  flue  gases : 

«          £ 

g  g  .      1  d  x          Z 

a  %6        y  6        ~  V.       °.          o.        j.., 

Date.  E  ££         ££ 


Nov.  4. 

H 
10  o'cl 

£^ 
Qkfc 

t! 

Q  0 

ock 

If 

No  5 

~5*4 

g  §      s  -  8 

X'  o3            oi  '£  « 
OP4          OCPn 
11  6          00 

S  Nitroge 
5  Per  Cen 

Nov.  4. 

11 

'           No   11 

2  2 

16  6          00 

81  ° 

Nov    4. 

32 

No  11 



2  8 

15  2          00 

82  0 

Nov    4. 

1 

No  5 

5  6 

j9  2          00 

«9  O 

Nov     4  . 

No   11 

3  2 

15  0          00 

XI    S 

Nov.   4. 

r> 

No  5 

5  8 

11  8          00 

82  4 

Nov    4. 

3 

No  11 

2  0 

1  a  K            oo 

Q-l     K 

Nov.   4. 

4 

No  5 

4  8 

13  0          00 

82  2 

Nov    4 

5 

No  11 

3  0 

15  5          00 

0-1     K 

Nov    4 

6 

No  5 

4  9 

00    0 

Nov.   5  . 

8 

No  5 

4  5 

13  1          00 

82  4 

*A11  the  gas  analyses  given  in  the  table  were  made  by  means 
of  the  Orsat  apparatus.  Occasionally  the  quantity  of  carbonic 
acid  ascertained  by  means  of  this  apparatus  was  controlled  by 
means  of  Stammer's  burette  and  Scheibler's  apparatus  and  found 
to  correspond.  For  very  accurate  analyses  it  is  advisable  to  use 
Hempel's  apparatus.  But  for  technical  gas  analyses  the  Orsat 
apparatus  is  more  convenient,  because  it  enables  one  to  work 
more  rapidly,  is  handier  and  is  sufficiently  accurate.  In  order 
not  to  disturb  the  work  in  the  boiler  house  during  the  campaign, 
low-pressure  boiler  No.  n  and  the  high-pressure  boilers  Nos.  5 
and  4  were  appointed  for  observing  and  examining  purposes,  and 
the  gas  samples  were  drawn  directly  from  the  boilers,  namely, 
between  the  draught  damper  and  the  flue. 


Date. 


Nov. 

5 

10       " 

Nov. 

11 

Nov. 

5  

12 

Nov 

5 

1 

Nov. 

5  

2 

Nov. 

5  

4 

Nov. 

5  

3 

Nov. 

5  

5 

Nov. 

6  

10 

Nov. 

6  

11 

Nov 

6 

12 

Nov. 

6  

1 

Nov. 

fi  

2        " 

Nov. 

6 

3 

Nov. 

6  

4 

Nov. 

6  

5 

Nov. 

7 

10 

Nov. 

7  

11 

Nov. 

7  

12 

Nov. 

7  

1 

Nov. 

7  

«> 

Nov. 

7  

3 

Nov. 

7  

5 

Nov. 

7  

6 

Nov. 

8-9  

9 

Nov. 

8-9  

10 

Nov. 

8-9  

11 

Nov. 

8-9  

1 

Nov. 

8-9  

2 

Nov. 

8-9  

3 

Nov. 

8-9  

5 

Nov. 

8-9  

6 

Nov. 

9-10.  .  . 

7 

Nov. 

9-10... 

9 

Nov. 

9-10.  .  . 

11 

Nov. 

9-10.  .. 

1 

Nov. 

9-10.  .. 

3 

Nov. 

9-10.  .. 

5 

Nov. 

10-11.  . 

7 

Nov. 

10-11.  . 

9 

Nov. 

10-11.  . 

11 

Nov. 

10-11.  . 

1 

Nov. 

10-11.. 

3 

Nov. 

10-11.  . 

5 

Nov. 

11-12.  . 

8 

Nov. 

11-12.  . 

10 

Nov. 

11-12.  . 

12 

Nov. 

11-12.  . 

2 

Nov. 

11-12.  . 

4 

Nov. 

11-12.  . 

6 

Nov. 

11-12.  . 

7 

Nov. 

12-13.  . 

8 

Nov. 

12-13.  . 

10 

Nov. 

12-13.  . 

12 

Nov. 

12  13.  . 

2 

Nov. 

12-13.  . 

4 

Nov. 

12-13.  . 

6 

1 

No.  11 

NO.  ii 

|l 

^  £ 

.HP'S 
ffiffl 

No.'  5 

No  5 

Carbonic 
^P^Acid,  CO  2 
35  ^oco  Per  Cent. 

gs 

dS 

15.3 
13.6 
14.9 
13.6 

-.--.-Carbonic 
ggggOxide.  CO 
Per  Cent. 

gc 

8L« 

2? 

81.8 
81.4 

82.4 
81.8 

No.  11 

No  5 

2.6 

4.8 

16.4 
15.2 

0.0 
0.0 

81.0 
80.0 

No  5 

5.4 

13.4 

0.0 

81  2 

No  11 

o   o 

14  8 

00 

81  4 

No  11 

r>  g 

15  6 

0  0 

81  6 

No.  11 

No   5 

3.0 
4  1 

15.5 
14  4 

0.0 

0  0 

81.5 
81  5 

No.  11 

No  5 

3.4 
3  8 

14.9 
15  4 

0.0 
0  0 

81.7 
80  8 

No.  11 

No  5 

3.2 

6  2 

15.3 
11  6 

0.0 

0  0 

81.5 
82  2 

No.  11 
No  ii 

No'.'  5 

3.6 
6.4 

5  8 

15.1 
11.8 
I9  8 

0.0 
0.0 
0  0 

81.3 
81.8 
81  4 

No  5 

7  6 

11  4 

O'O 

81  0 

No.  11 

No.  ii- 

No.'  5 

7.5 

7.4 
8.6 

12.0 
12.1 
12.0 

0.0 
0.0 
0.0 

80.5 
80.5 
79.4 

No.  5 

7.0 

12.4 

0.0 

80.6 

No.  5 

7.0 

12.4 

0.0 

80.6 

No.  5 

7.8 

11.1 

0.0 

81.1 

No.  5 
No.  5 
No.  5 

6.0 
9.2 

8.5 

14.6 
9.4 

10  5 

0.0 
0.0 
0  0 

79.4 
81.4 
81  0 

No.  5 
No.  4 
No.  4 
No.  4 
No.  4 
No.  4 
No.  4 
No.  4 

7.6 
4.5 
6.5 

8.2 
6.4 
6.2 
7.4 
6  8 

12.4 
16.3 
13.1 
11.2 
13.9 
13.4 
12.0 
12  8 

0.0 
0.0 
0.0 
0.0 
0.0 
0.0 
0.0 
0  0 

80.0 
79.2 
80.4 
80.6 
79.7 
80.4 
80.6 
80  4 

No.  4 

7  3 

11  6 

0  0 

81  1 

No  5 

8  0 

12  2 

0  0 

79  8 

No.  4 
No.  4 

No  5 

8.3 
9.6 
10  0 

11.7 
9.5 
9  1 

0.0 
0.0 
00 

80.0 
80.9 
80  9 

No  4 

8  3 

10  2 

0  0 

81  5 

No  11 

7  8 

19  2 

0  0 

SO  0 

No  4 

9  0 

10  6 

0  0 

80  4 

No.  11 

No  4 

6.8 
11  6 

14.0 
6  8 

0.0 
0  0 

79.2 
81  6 

No.  11 

No  4 

6.8 
10  3 

13.8 
9  9 

0.0 
0  0 

79.4 
79  8 

No.  11 

No'  4 

7.4 
11  2 

12.6 
8  6 

0.0 
0  0 

80.0 
80  2 

No.  11 

No  4 

8.0 
10  6 

12.0 
8  8 

0.0 
0  0 

80.0 
80  6 

No'.'ii 

No.  4 
No  4 

9.9 

7.8 
9  4 

9.6 
12.6 
10  0 

0.0 
0.0 
0  0 

80.5 
79.6 
SO  6 

No.  11 
No.  11 

No  4 

5.4 
6.8 

7  4 

14.3 
12.6 
12  3 

0.0 
0.0 
0  Q 

80.3 
80.6 
80  3 

8 

Date. 


*l 

c  o 


gs 


Nov.    13-14 
Nov.  13-14 
Nov.   13-14 

12 
1 
2 

( 

No.  4 
No.  4 

No  4 

5.6 
4.3 
6  0 

14.2 
16.3 
13  2 

0.0 
0.0 
0  0 

80.2 
79.4 
80  8 

Nov.    13-14 
Nov.   13-14 
Nov.   13-14 

3 

4 
5 



No.  4 
No.  4 
No  4 

7.8 
8.0 
11  1 

11.2 
11.4 
8  3 

0.0 
0.0 
0  0 

81.0 
80.6 
80  6 

Nov.   15. 

10 

No  4 

8  0 

12  0 

00 

80  0 

Nov.   15. 

11 

No  4 

12  7 

5  3 

0  0 

82  0 

Nov.    15. 

1 

No  11 

10  0 

7  9 

0  0 

82  1 

Nov.   15. 

0 

No  4 

9  7 

9  9 

0  0 

80  4 

Nov.   15. 

4 

No  11 

6  4 

13  6 

0  0 

80  0 

Nov.   15. 

5 

No  4 

8  5 

10  5 

00 

81  0 

Nov.  15.    . 

6 

No.  11 

7.7 

11.8 

0.0 

80.5 

In  the  first  place,  it  is  noticeable  that  no  one  of  the 
analyses  shows  contents  of  carbon  monoxide.  This 
proves  that  in  the  boiler  house  in  all  cases  a  considerable 
surplus  of  air  was  used.  In  the  second  place,  it  is  strik- 
ing that  all  the  analyses  of  the  high-pressure  boilers, 
with  only  one  exception,  showed  a  composition  much 
more  favorable  than  the  analyses  of  the  low-pressure 
boiler. 

In  the  first  three  days  (on  the  4th,  5th  and  6th  of 
November)  the  flue  gases  had  the  following  average 
composition : 

%CO2    %O     %CO     %N 

November  4,  5  and  6 — Boiler  No.     5..  5.1        13.1         o.o        81.8 
November  4,  5  and  6 — Boiler  No.  n..   3.0        15.5        o.o        81.5 

Thus  in  every  100  liters  of  the  flue  gases  of  the  high- 
pressure  boiler  No.  5  were  contained  5.1  liters  of  carbon 
dioxide  and  13.1  liters  of  oxygen.  Taking  into  considera- 
tion that  the  weight  of  I  liter  of  carbonic  acid  and  of 
oxygen  equals  1.966  grams  and  1.43  grams,  respectively, 
we  have:  5.1  X  1.966=10.03  grains  of  carbonic  acid, 

10.03  X  12 

of    which  -  =  2.74    grams    of    carbon    and 

44 


io.o3  X  32 

-  —  7.29    grams    of    oxygen.      Further,    13.1 

44 

liters  of  oxygen  =  13.1  X  1-43  =  18.7 3  grams  of  oxygen. 
Consequently,  in  100  liters  are  contained  2.74  grams  of 
carbon  and  7.29  -j-  18.73  =  26.02  grams  of  oxygen.  Thus 
2.74  grams  of  carbon  united  with  26.02  grams  of  oxygen, 

26.02  X  100 

corresponding  to  -  -112.64  grams  of  air,  or 

23.1 

112.64 
i  pound  (gram)   of  carbon  united  with  -         —=141.11 

2.74 
pounds   (grams)   of  air;  or   I   pound  of  our  coal  used 

10.70 
41.11  X-      -  =  38.12  pounds  of  air. 

11-54 

In  like  manner  we  have:  In  every  100  liters  of  the 
flue  gas  in  the  low-pressure  boiler  No.  n  were  contained 
3.0  liters  of  carbonic  acid  and  15.5  liters  of  oxygen;  3.0 

12 
liters  of  carbonic  acid  consist  of  3.0  X  1.966  X  —  =  1.61 

44 
32 
gr.  of  carbon  and  3.0  X  1.966  X  —  =  4.29  gr.  of  oxy- 

44 

gen.  Besides  this,  15.5  liters  of  oxygen  =  15.5  X  1-43  — 
22.16  gr.  of  oxygen.  Consequently  in  100  liters  of  the 
flue  gas  were  contained  1.61  gr.  of  carbon  and  4.29  + 
22.16  =  26.45  gr.  of  oxygen.  Or  1.61  gr.  of  carbon 
united  with  26.45  g1'-  °f  oxygen  corresponding  to  26.45  X 

100 

-=  114.5  gr-  °f  air;  J  rt>-    (gram)   of  carbon  united 
23.1 

10 


1 14.5 

with =  71.12  Ibs.  (grams)  of  air;  i  Ib.  of  our  coal 

1.61 

10.70 
used  71.12  X  -     -  =65.94  Ibs.  of  air. 

H-54 

Now,  what  quantity  of  air  per  pound  of  coal  was  used 
in  the  following  days? 

During  the  last  five  days  together  the  flue  gases  were 
of  the  following  average  composition : 

%CO2  %O  %CO  %N 
Nov.  10-11,  11-12,  12-13,  13-14  and  15 — 

Boiler    No.      5 10.0  9.1  o.o  80.9 

Boiler    No.      4 9.1  10.2  o.o  80.7 

Boiler    No.    11 7-4  12.5  o.o  80.1 

In  loo  liters  of  the  flue  gas  in  boiler  No.  5  were  con- 
tained 10.0  liters  of  carbonic  acid  and  9.1  liters  of  oxygen, 
or  i  o.o  X  1.966  =  19.66  gr.  of  carbonic  acid,  of  which 

12  32 

19.66  X  — *=  5.36  gr.  of  carbon  and  19.66  X  —  =  14.30 

44  44 

gr.  of  oxygen.  Besides,  9.1  liters  of  oxygen  =9.1  X 
1.43  =  13.01  gr.  of  oxygen.  Thus  in  100  liters  are 
contained  5.36  gr.  of  carbon  and  14.30+  13.01  =  27.31 
gr.  of  oxygen;  consequently  5.36  pounds  (or  grams)  of 
carbon  united  with  27.31  pounds  (or  grams)  of  oxygen 

IOO 

corresponding  to  27.31  X  -    -=  118.23  Ibs.  of  air.     Or 

23.1 
118.23 

i  Ib.  of  carbon  used =  22.06  Ibs.  of  air.     Conse- 

5-36 

10.7 
quently,  i  Ib.  of  our  coal  used  22.06  X  -    -  =  20.45  Iks. 

H-54 
of  air. 

11 


In  like  manner  we  find :  In  100  liters  of  the  flue  gas 
in  boiler  No.  4  were  contained  9.1  liters  of  carbon  dioxide 
and  10.2  liters  of  oxygen  corresponding  to  4.88  gr.  of  car- 
bon and  27.60  gr.  of  oxygen.  Or 

4.88  pounds    (grams)    of  carbon  used  27.60  pounds    (grams)    of 

oxygen. 

i  pound  (gram)  of  carbon  used  5.66  pounds  (grams)  of  oxygen, 
corresponding  to  24.50  pounds  of  air. 

107 
i    pound    of   our  coal    used    24.50  X  -  =22.72   pounds    of 

H-54 
air. 

Similarly  we  have :  100  liters  of  the  flue  gas  in  boiler 
No.  ii  contain  7.4  liters  of  carbonic  acid  and  12.5  liters 
of  oxygen  corresponding  to  3.97  gr.  of  carbon  and  28.45 
gr.  of  oxygen.  Consequently: 

3.97  pounds  (or  grams)  of  carbon  used  28.45  pounds  (or  grams) 

of  oxygen. 

i  pound   (or  gram)   of  carbon  used  7.17  pounds    (or  grams)    of 
oxygen,  corresponding  to  31.04  pounds   (or  grams)   of  air. 

10.7 
i    pound    of  our    coal    used    31.04    X    -         -  =  28.78    pounds    of 

n-54 
air. 

In  order  to  have  the  figures  in  the  above  calculation   pre- 
sented more  clearly,  they  are  summarized  as  follows : 

Pounds  of  Air. 

i  Ib.  of  carbon  uses  theoretically  for  its  combustion....       H-54 
i  Ib.  of  our  coal  uses  theoretically  for  its  combustion..       10.70 

i  Ib.  of  our  coal  ought  to  use,  according  to  the  best  prac- 
tical experience,  from  about 16  to  21 

i  Ib.  of  our  coal  used  actually  in  the  first  three  days  in 

boiler  No.  5 38.12 

i  Ib.  of  our  coal  used  actually  in  the  first  three  days  in 

boiler  No.  1 1 65 . 94 

i  Ib.  of  our  coal  used  actually  in  the  last  five  days  in 

boiler  No.  5 20 . 45 

i  Ib.  of  our  coal  used  actually  in  the  last  five  days  in 

boiler  No.  4 22.72 

12 


i   Ib.  of  our  coal  used  actually  in  the  last  five  days  in 

boiler    No.    n 28.78 

So  we  observe  that  in  the  first  three  days,  when  I  did  not 
regulate  the  air  necessary  for  burning,  in  the  .high-pressure 
boiler  No.  5,  about  four  times  as  great  a  quantity  of  air  was 
used  as  theory  requires,  and  about  two  times  as  great  a  quantity 
as  the  best  practical  experience  till  now  demonstrates ;  and  in 
low-pressure  boiler  No.  n  was  used  six  times  the  quantity  of 
air  required  by  theory,  and  from  three  to  four  times  the  air 
required  by  the  best  practical  experience. 

These  figures  changed  essentially  in  the  last  five  days,  during 
which  the  air  necessary  for  burning  was  regulated  by  me. 

In  low-pressure  boiler  No.  n  only  from  one-third  to  one- 
half  more  air  was  used  than  the  best  experience  proves,  and  in 
the  hjgh-pressure  boilers  No.  4  and  No.  5  the  quantities  of  air 
used  for  burning  agree  very  nearly  with  the  best  practice. 

Here  I  wish  to  note  that  during  the  campaign  the  grate  in 
boiler  No.  4  was  shortened,  i.  e.,  two  feet  was  covered  with 
fireproof  brick,  so  that  the  grate  surface  was  6  feet  by  4  feet, 
equals  24  square  feet  (instead  of  6  feet  by  6  feet).  It  follows 
from  the  figures  mentioned  that,  although  the  combustion  gases 
in  boiler  No.  4  were  more  favorable  than  in  boiler  No.  n,  yet 
their  composition  was  not  generally  better  than  in  boiler  No.  5. 
In  consequence,  it  was  not  deemed  advisable  to  shorten  the  grates 
in  the  other  boilers. 

At  all  events,  it  is  evident  that  the  greater  the  overplus  of 
air  penetrating  the  grates  from  the  outside  and  passing  up  the 
chimney,  the  greater  is  the  loss  of  heat  in  the  boiler  house.  Let 
us  ascertain,  in  the  first  place,  the  amount  of  calories  which  one 
kilogram  of  our  coal  is  able  to  furnish,  and,  in  the  second  place, 
determine  the  losses  of  heat  caused  py  the  overplus  of  air  pass- 
ing up  the  chimney.  The  coal  under  consideration  has  the 
following  composition : 

Moisture.    Ash.    Sulphur.    Carbon.     Hydrogen      Oxygen  -f  Nitrogen. 

(by  difference.) 
1.44        9.14       0.57  78.10  4.8  5.95 

According   to    Dulong   the    heating   value    of   a    coal    equals 


18 


8,080  C  +  28,800   H I  +  2,500  S  —  600  W 

I «. 

IOO 

in  which  C,  H,  O,  S  and  W  represent  the  percentage  of  carbon, 
hydrogen,  oxygen,  sulphur  and  moisture.  Substituting  in  this 
formula  the  values  found  by  the  analyses,  it  becomes  : 

8,080X78-1+28,800     4.8 +2,500X0.57—600X1-44 


IOO 

7,485  calories.     Now,  of  this  quantity  of  heat  a  part  is  lost  by 
the  hot  gases  passing  up  the  chimney. 

According  to  the  analysis  of  the  coal,  in  I  kilogram  of  the 
latter  are  contained  781  gr.  of  carbon,  of  which,  say,  2  per  centt 
fall  through  the  grate  into  the  ashes,  so  that  there  remain 

78i  X2 
781 —  =  in  round  number  765  gr.,  for  the  formation  of 

IOO 


*Nitrogen  may  be  neglected  because  it  affects  the  result 
less  than  I  per  cent.  Soft  coal  contains  generally  much  less 
nitrogen  than  oxygen,  and  even  in  a  very  unfavorable  case, 
if  our  coal  contains  2  per  cent  nitrogen,  we  find  : 

8,080X78.1+28,800      4-8 —      +2,500X0.57  —  600X1.44 

8    ' 

IOO 

7>557  calories.     Consequently,  the  difference  equals  7,557  —  7,485 

72 
=  72  calories,  or  — —  =  0.96%. 

7,485 

Similarly,  for  the  sake  of  simpleness,  it  was  above  assumed 
that  the  air  consists  of  20.92  volumes  of  oxygen  and  79.08  vol- 
umes of  nitrogen,  against  which  0.04  volumes  of  carbon  dioxide 
really  contained  in  the  air  were  neglected. 

tExaminations  of  the  combustible  part  of  the  ashes,  which 
fell  through  the  grate,  made  by  me  in  a  sugar  factory  of  Ger- 
many, under  similar  conditions,  give  me  the  right  to  this 
assumption. 

14 


carbonic  acid  gas.     In  the  first  three  days  the  combustion  gases 
in  boiler  No.  1 1  were  of  the  average  composition : 

%  CO,  %  p.  %  CO.  $  N. 

3-0  15.5  o.o  81.5 

Three   liters   of  carbonic   acid   weigh  3X1-966=5.898   gr.   of 

12 
carbonic  acid  corresponding  to  5.898  X  —  =  1.6085  gr.  of  carbon. 

44 

In  consequence,  1,6085  gr-  of  carbon  furnish  3.0  liters  of 
carbonic  acid ;  765  gr.  of  carbon  furnish  t  liters  of  carbonic 

3-0  X  765 
acid;    t:    3.0  =  765:    1.6085;    t  =  —  =1,426    liters  =  1.426 

1.6085 
cubic  meters  of  carbonic  acid. 

The  quantity  of  oxygen  results  from  the  proportion  3.0:   15.5 

15.5  X  1,426 
=  1,426:     s;     s=  =  7,368    liters  =  7,368    cubic   meters 

3-0 
of  oxygen. 

The   quantity   of  nitrogen   results   from   the   proportion   3.0: 

81.5  X  1,426 
81.5  =  1,426:    r;    r  =  —  =38,740    liters  =  38.740    cubic 

3-0 
meters  of  nitrogen. 

Thus,  i  kilogram  of  coal  furnishes  1.426  cubic  meters  of 
carbonic  acid,  7.368  cubic  meters  of  oxygen  and  38.740  cubic 
meters  of  nitrogen. 

In  order  to  ascertain  the  quantity  of  heat  that  each  gas 
carries  up  the  chimney,  the  weight  of  the  gas  (i.  e.,  volume  X 
specific  gravity)  must  be  multiplied  by  the  specific  heat  and  by 
their  rise  of  temperature.  The  temperature  of  the  air  entering 
the  grates  was  20°  Celsius;  that  of  the  chimney  gases  is  mostly 
between  200°  and  300°  C.  Let  us  suppose  their  average  tem- 
perature was  250°  C.*  Since  the  temperature  of  the  escaping 
gases  varies  in  different  factories,  I  will  calculate  the  losses 
for  all  the  three  temperatures.  The  rise  in  temperature  is  then 

250  —  20  =  230°  C,,  300  —  20  =  280°  C.,  2CO  —  20  =  l8o°  C. 


This   temperature  could   not   be   determined   exactly  in   the 
bsence  of  a  pyrometer. 

13 


Weight  of  Rise  of 

Cubic  Cu.   M.       Sp.     Temp., 
Meters.  Kilogr's.  Heat.     Gels.     Cals. 
At  250°   C*,  carbon  dioxide 

carries  away  1.426  X  1.966  X  0.217  X  230  =     139.9 

At  250°  C,   oxygen   carries 

away  ..'... . .  7-368  X  i-43    X  0.218  X  230  —    528.3 

At  250°   C.,  nitrogen  carries 

away    .38.740  X  1.26    X  0.244  X  230  =  2,739.4 

Total     47-534 

Furthermore,  the  quantity  of  heat  carried  off  by  the  water 
vapor  must  be  calculated.  The  aqueous  vapor  proceeds  from 
the  combustion  of  hydrogen  contained  in  the  coal,  from  its 
moisture  and  from  the  air  penetrating  the  grates.  According 
to  the  analysis,  the  coal  contains  4.8  per  cent  =  0.048  kilograms 
of  hydrogen  per  kilogram  of  coal.  One  kilogram  of  hydrogen 
produces  in  burning  9  kilos,  of  water,  consequently  0.048  kilo- 
gram of  hydrogen  produces  0.048  X'  9 =3  0.432  kilograms  of 
water.  The  quantity  of  moisture  in  the  coal  is  1.44  per  cent  — - 

Weight  of 

Cubic  Cu.   M.       Sp.     Rise  of 
Meters.  Kilogr's.  Heat.  Temp.    Cals. 
*At  300°   C,  carbon  dioxide 

carries    away     1.426  X  1.966  X  0.217  X  280  =     170.3 

At  300°  C,  oxygen  carries 

away    7.368  X    1.43X0.218X280—     643.1 

At  300°  C,  nitrogen  carries 

away    38.740  X    1.26X0.244X280  =  3,334.9 

At    300°  C.,    water    vapor 

carries    away    0.881    kgms.    X  0.481  X  280=     118.7 

Total 4,267.0 

4,267.0 
Total    loss   equals   4,267.0   calories    or —    — XIoo  =  57.o^ 

7485 

Cals. 
At  200°  C,  carbon  dioxide 

carries    away    1.426  X  1.966  X  0.217  X  180  =     109.5 

At  200°  C,  oxygen  carries 

away    7,368  X    i. 43  X  0.218  X  .180  =    413.4 

At  200°  C,  nitrogen  carries 

away    38.740  X    1.26X0.244X180  =  2,143.8 

At    200°  C.,    water    vapor 

carries  away 0.881    kgms.    X  0.481  X  180=      76.3 


Total 2,743.0 

2,743 
Total    loss    equals    2,743    calories    or    -      —  X  100  =  36.6  ^ 

7,485 
1C 


0.014  kilogram  per  i  kilogram  of  coal.  The  amount  of  air 
entering  the  grates  equals  the  amount  of  combustion  gas — 
47-534  cubic  meters  —  as  it  follows  from  equation  II.  The 
quantity  of  water  vapor  per  cubic  meter  of  the  air  was 
found  by  me  to  be  9.16  grams.  Consequently  the  total  volume 
of  47-534  cubic  meters  contains  9.16  X  47-534  =  0.435  kilograms. 
So  that  the  total  quantity  of  water  vapor  per  kilogram  of  coal 
=  0.4324-0.0144-0.435=0.881  kilogram.  The  quantity  of  heat 
carried  away  by  the  water  vapor  equals  its  weight  X  its  spec, 
heat  X  rise  of  temperature,  i.  e.,  0.881  X  0.481  (sp.  heat)  X  230 
(rise  of  temp.)  =97.5  calories. 

Adding  to  the  losses  caused  by  carbon  dioxide,  oxygen 
and  nitrogen,  we  have  139.9  -f-  528.3  -f  2,739.4  +  97.5  =  3,505.1 
calories.  Since  I  kilogram  of  our  coal  furnishes  7,485  calories, 

3,505-1 
the  total   loss  expressed  in  percentage   ratio  gives  -       —  X  100 

7,485 

=  46.8  per  cent.  These  figures  we  have  found  for  boiler  No. 
ii  in  the  first  three  days. 

In  the  s,?me  manner  we  may  calculate  for  boiler  No.  5. 
The  average  composition  of  its  gases  was : 

$C02  £  O.  £  CO.  £  N. 

5-i  13-1  o.o  81.8 

Now,  5.1   liters  of  carbon  dioxide  =  5.1  X  1.966  =  10.027  gr. 

of  carbon   dioxide  corresponding  to  2.735  Sr-  of  carbon.     Thus 

2-735   gr.    of   carbon    furnish    5.1    liters    of   carbon    dioxide;    765 

gr.    of   carbon    furnish    x1   liters   of  carbon   dioxide,     x1:   5.1  = 

5.1X765 
765  :    2.735  ;    x1  =  —          -  =  1,426    liters  =  1.426    cubic    meters 

2-735 
of   carbon    dioxide. 

The  quantity  of  oxygen   is   determinable   by  the  proportion 

1,426  X  I3-I 
5.1 :  13.1  =  1,426 :     y1 ;     y1  =  — .  =  3,663     liters  =  3.663 

5.1 

cubic  meters  of  oxygen. 

The  quantity  of  nitrogen   is   ascertained  by  the  proportion : 

1,426  X  81.8 
5.1:81.8=1,426:     z1;     z1  —  —  =  22,872     liters  =  22.872 

5-1 
cubic  meters  of  nitrogen. 

17 


The  amount  of  calories  that  each  gas  carries  up  the  chimney 
is: 

Weight  of  Rise  of 

Cubic      Cu.   M.      Sp.     Temp., 
Meters.  Kilogr's.  Heat.     Cels.     Cals. 
At     250°      C,     for     carbon 

dioxide   1.426  X  1.966  X  0.217  X  230--=     139.9 

At  250°   C,   for  oxygen 3.663  X    1.43X0.218X230=     262.6 

At  250°    C,   for   nitrogen.  .  .22.872  X    1.26  X  0.244  X  230  =  1,617.3 


Total 27.961 

Let  us  now  calculate  the  weight  of  aqueous  vapor.  Mois- 
ture per  kilogram  of  coal  there  is  0.014  kilo  water  vapor ; 
0.048  kilogram  of  hydrogen  furnishes  in  burning  0.048  X  9  —  0.432 
kilo,  water  vapor.  Aqueous  vapor  penetrating  the  grates  with 
the  air  equals  27.961  (cu.  m.)  X  9-i6  gr.  =0.256  kilo  water 
vapor.  Total,  0.702  kilograms  of  water  vapor. 

In  consequence,  the  quantity  of  heat  carried  up  the  chimney 
by  the  water  vapor  is  0.702  (kilograms)  X  0.481  (spec,  heat)  X 
230  (rise  of  temp.)  =77.7  calories.  Hence  the  total  loss  of 
heat  carried  up  the  chimney  by  all  the  gases  together  equals 

2,097.5 
139-9  +  262.6  +  1,617.3  +  77.7  =  2,097.5    calories,    or   -        —  X  100 

7,485 
=  28.0  per  cent.* 

In  the  last  five  days  the  losses  may  be  calculated  as  follows : 

In  boiler  No.  n  the  flue  gas  was  of  the  average  composi- 
tion : 

%  C02  £0.  0  CO.  0  N. 

7.4  12.5  o.o  80.1 

*At  300°  C.  the  losses  are  calculated  as  follows:  For  car- 
bonic acid,  170.3  calories;  for  oxygen,  319.7  calories;  for  nitro- 
gen, 1,968.9  calories,  and  for  aqueous  vapor,  94.5  calories.  Alto- 
gether the  loss  up  the  chimney  equals  170.3  +  3T9-7  +  1,968.9 

2,553-4 
+  94.5  =  2,553.4   calories,  or X  100  =  34.1   per  cent. 

7,485 

At   200°    C.    the   losses   are   calculated   in    like   manner   for: 

Carbon  dioxide,  109.5  calories;  oxygen,  205.5  calories;  nitrogen, 

1,265.7   calories,    and    aqueous    vapor,    60.8    calories.      Altogether 

the  loss  up  the  chimney  equals    109.5 -{- 205.5 -4- 1,265.7  +  60.8  = 

1,641.5 

1,641.5  calories,  or X  100  =  21.9  per  cent. 

7,485 

18 


Thus  we  have :  7.4  liters  of  carbon  dioxide  equals  7.4  X 
1.966  =  14.548  gr.  of  carbon  dioxide,  corresponding  to  3.968  gr. 
of  carbon. 

Consequently,  3.968  gr.  of  carbon  generate  7.4  liters  of  car- 
bon dioxide ;  765  gr.  of  carbon  generate  u1  liters  of  carbon  diox- 

7  A  X  705 
ide.     u1 :  7.4  =  765  :  3.968 ;  u1  =  —  —  =  1,426  liters  =  1.426  cu- 

3.968 
bic  meters  of  carbon  dioxide. 

The  volume  of  oxygen  is  found  by  the  proportion  7.4:  12.5  = 

12.5  X  1,426 
1,426  :t1;t1=  =2,409  liters  =  2.409  cubic  meters  of 

7-4 

oxygen. 

The  quantity  of  nitrogen  is   found  by  the  proportion:   7.4: 

1,426X80.1 
80. i  =  1,426 is1;    s1  =  =15435    liters  =  15-435    cubic 

7-4 
meters  of  nitrogen. 

The  losses  are  calculable  as   follows: 

Weight  of  Rise  of 

Cubic     Cu.  M      Sp.      Temp. 
Meters.  Kilogr's.  Heat.     Cels.     Cals. 
At     250°     C.,     for     carbon 

dioxide    1.426  X  1.966  X  0.217  X  230  =     139.9 

At    250°    C,    for    oxygen..  2.409X1.43    X  0.218X230=-     172.7 
At   250°    C,    for   nitrogen.  .15.435  X  1.26    X  0.244  X  230=  1,091.4 


Total    19.270 

Now  we  proceed  to  calculate  the  quantity  of  aqueous  vapor 
which  passes  up  the  chimney: 

48  gr.  of  hydrogen  produce  in  burning  48  X  9 =  432  gr.  = 
0.432  kilograms  of  water  vapor. 

Moisture  per  kilogram  of  coal  equals  0.014  kilograms  of 
water  vapor.- 

The  quantity  of  water  vapor  entering  the  grates  with  the 
air  equals  19.27X9-16  =  0.177  kilograms  of  water  vapor. 

Total,  0.623   kilograms  of  water  vapor. 

The  amount  of  heat  carried  off  by  the  water  vapor  equals 
0.623  (kilograms)  X  0.481  (sp.  heat)  X  230  (rise  of  temp.)  = 
68.9  calories.  Hence  the  total  loss  of  heat  equals  139.9  +  172.7 

19 


1,472-9 
-[-1,091.4  +  68.9=1,472.9    calories,    or    -        —  X  100=19.7    per 

7,485 
cent* 

The  calculation  for  boiler  No.  5  takes  place  in  the  same 
manner.  The  composition  of  its  combustion  gases  was  as  fol- 
lows : 

%  CO,  %  O.  $  CO.  0  N. 

10.0  9.1  o.o  80.9 

Ten  liters  of  carbon  dioxide  equal  10.0  X  1.966  —  1 9.66  gr. 
of  carbon  dioxide,  corresponding  to  5.362  gr.  of  carbon. 

Now,  5.362  gr.  of  carbon  produce  10.0  liters  of  carbon 
dioxide.  765  gr.  of  carbon  produce  x"  liters  of  carbon  dioxide. 

10.0  X  765 
x" :  IG.O  =  765  :  5.362 ;  x"  =  -  —  =  1,426  liters  ==  1.426  cubic 

5-362 
meters  of  carbon  dioxide. 

The  quantities  of  oxygen  and  nitrogen  are  determinable  by 
the  following  proportions : 

1,426  X  9-1 

10.0 :  9.1  =  1,426 :  y" ;  y"  =  —      —  =  1,298  liters  ==  1.298 

i  o.o 

1,426  X  80.9 
cubic  meters  of  oxygen;  10.0:80.9  =  1,426:?:";  z"  = 

10.0 
=  11,536  liters  =  11.536  cubic  meters  of  nitrogen. 


*At  300°  C.  the  losses  are  calculated  in  like  manner,  namely, 
for:  Carbon  dioxide,  170.3  calories;  oxygen,  210.3  calories; 
nitrogen,  1,328.7  calories,  and  water  vapor,  83.9  calories.  To- 

1,793-2 
gether  all  the  gases  carry  off  1,793.2  calories,  or  -       —  X  100  = 

7,485 
24.0  per  cent. 

At    200°     C.    the    losses    are,    for:     Carbon    dioxide,    109.5 
calories ;  oxygen,  135.2  calories ;  nitrogen,  854.2  calories,  and  for 
water    vapor,    53.9   calories.      Together    all    the    gases    carry    off 
1,152.8 

1,152.8  calories,  or X  100=  15.4  $. 

7,485 

20 


The  calculation  of  the  losses  is  as  follows : 

Weight  of  Rise  of 

Cubic     Cu.  M      Sp.     Temp. 
Meters.  Kilogr's.  Heat.     Cels.     Cals. 
At    250°  C,    carbon    dioxide 

carries    off    1.426  X  1.966  X  0.217  X  230  —  139.9 

At  250°  C,  oxygen  carries  off  1.298  X  i-43    X  0.218  X  230=   93.1 
At     250°  C.,     nitrogen     car- 
ries   off     11.536X1.26    X  0.244  X  230  =  815.7 


Total     14.260 

The  calculation  of  the  quantity  of  aqueous  vapor  passing  up 
the  chimney  is  executed  as  follows : 

48  gr.  of  hydrogen  furnish  in  burning  0,432  kilos, 
of  water  vapor ;  moisture  per  .kilogram  of  coal  equals  0.014 
kilos,  of  water  vapor ;  water  vapor  entering  the  grates  with 
the  air  equals  14.26  (cu.  m.)  X  9-i6  (grams)  =0.131  kilos,  of 
water  vapor ;  total,  0.577  kilos,  of  water  vapor,  which  carries 
up  the  chimney  0.577  (kilos.)  X  0.481  (sp.  heat)  X  230  (rise  of 
temp)  =  63.8  calories. 

The  total  loss  of  heat  that  all  the  gases  carry  off  equals 
J39-9  +  93-1  -f  815.7+  63.8  =  1,112.5  calories,  corresponding  to 
1,112.5 

—  X  100  =  14.9  per  cent.* 
7,485 

Let  us  recapitulate :  In  the  first  three  days — as  I  only  tried 
to  ascertain  the  manner  and  quality  of  the  work  in  the  boiler 
house,  and  I  did  not  regulate  the  air  entering  the  grates — the 
loss  of  heat  in  boiler  No.  n  was  46.8  per  cent,  at  250°  C.  (57.0^ 
and  36.6%  at  300°  C.  and  200°  C.,  respectively)  ;  likewise  the  loss 
in  boiler  No.  5  was  28.0  per  cent  at  250°  C.  (34.1%  and  21.9%  at 
300°  C.  and  200°  C.,  respectively).  These  conditions  were  im- 


*At  300°  C.,  the  losses  were  found  as  follows :  For  carbon 
dioxide,  170.3  calories;  for  oxygen,  113.3  calories;  for  nitrogen, 
993.1  calories;  for  water  vapor,  77.7  calories;  together,  1,354.4 

1,354-4 
calories,  corresponding  to  -       —  Xioo=i8.i^. 

7,485 

At  200°  C,  the  losses  were  found :  For  carbon  dioxide,  109.5 
calories;  for  oxygen,  72.8  calories;  for  nitrogen,  638.4  calories, 
and  for  water  vapor,  50.0  calories ;  together,  870.7  calories,  cor- 

870.7 

responding  to  X  100  =  n.6  ^. 

7,485 

21 


proved  essentially  in  the  last  five  days,  when  I  regulated  the  air 
necessary  for  burning,  namely:  In  boiler  No.  11  the  loss  of  heat 
was  19.7  per  cent  at  250°  C.  (24.0%  at  300°  C,  and  15.4%  at 
200°  C.)  ;  likewise  the  loss  in  boiler  No.  5  was  only  14.9  per  cent 
at  250°  C.  (18.1%  at  300°  C.  and  n.6%  at  200°  C.). 

In  other  words,  per  100  tons  of  coal  the  loss  in  the  first 
three  days  was  46.8  tons  in  boiler  No.  n,  and  28.0  tons  in  boiler 
No.  5;  the  loss  became,  instead,  in  the  last  five  days,  19.7  tons 
in  boiler  No.  n,  and  14.9  tons  in  boiler  No.  5  These  figures 
apparently  show  the  great  importance  of  a  correct  regulation  of 
the  air  necessary  for  burning.  The  losses  in  boiler  No.  4  were 
between  those  of  the  boilers  Nos.  n  and  5. 

I  am  sure  that  losses  caused  by  false  regulation  of  the  air 
necessary  for  burning  take  place  in  some  factories,  and  each  sugar 
house  that  uses  a  great  percentage  of  coal  per  100  parts  of  beets 
has  a  very  forcible  reason  in  the  first  place  to  think  of  false  regu- 
lation of  the  air,  and  should  try  to  remove  this  fault.  Certainly, 
during  the  campaign  the  factory  administration  has  a  great  mul- 
tiplicity of  cares,  in  order  to  get  sugar  of  good  quality  and  as 
high  a  yield  as  possible,  etc.,  so  that  it  is  hardly  in  a  position  to 
look  occasionally  in  the  boiler  house.  The  management  is  usu- 
ally satisfied  if  the  steam  gauges  of  the  boilers  show  sufficient 
pressure,  as  is  desired  in  the  factory  for  the  engines  and  for 
boiling  purposes. 

Whether  or  not  the  boiler  house  works  economically  is  cer- 
tainly a  question  of  great  importance,  which  a  correct  and  quali- 
fied administration  must  and  will  try  to  answer.  In  order  to 
work  economically  (supposing,  above  all,  a  correct  construction 
of  the  boiler  house  plant)  we  should  consider  the  regulation  of 
the  air  entering  the  grates;  in  the  second  place  the  qualities  oi 
the  fuel,  feed  water  and  steam. 

First  of  all  it  is  of  importance  that  the  grate  be  covered  with 
coal  on  its  whole  surface  as  uniformly  as  possible,  because  on 
places  where  the  grate  is  free  from  coal  the  air  enters  the  grate 
unproductively,  passing  up  the  chimney  as  not  being  properly  util- 
ized, and  increasing  the  waste  of  fuel.  On  the  other  hand,  where 
the  coal  lies  in  too  high  layers,  the  entering  of  the  air  is  more 
difficult,  whereby  the  active  grate  surface  is  decreased.  Only 
when  the  coal  lies  in  uniform  and  medium  layers  has  the  entering 
air  the  greatest  opportunity  to  come  into  close  contact  with  the 


glowing  coal  on  many  places,  whereby  the  oxygen  of  the  air 
can  be  utilized  in  the  best  possible  manner. 

Many  firemen  customarily  open  the  dampers  regulating  the 
draught  wide,  as  soon  as  the  steam  pressure  decreases,  or  they 
open  the  stokeholes  in  case  the  steam  pressure  and  the  glow  on 
the  grates  increase  too  much.  It  is  evident  that  these  manipula- 
tions are  incorrect,  because  lots  of  air  thereby  penetrates  the 
grates,  cooling  the  combustion  gases  as  well  as  the  boilers  and 
the  gas  channels.  It  is,  on  the  contrary,  more  suitable  to  regu- 
late the  air  as  equally  as  possible.  A  convenient  way  to  reach 
this  purpose  is  to  place  measuring  scales  along  the  chains,  which 
must  be  equal  and  which  must  run  on  pulleys,  in  order  to  regulate 
the  air  inlet.  The  scales  can  be  made  in  each  boiler  house  from 
shelves  painted  black  and  divided  by  means  of  white  lines  into 
inches  or  centimeters.  Before  the  beginning  of  the  campaign  the 
engineer  ought  to  ascertain,  and  then  to  tell  the  firemen,  what 
lines  of  the  scale  correspond  to  the  end  of  the  chain,  if  the  damper 
is  entirely  open,  half,  quarter,  etc.  Besides  the  separate  damp- 
ers in  each  boiler,  a  main  damper  ought  to  be  placed  where  the 
flue  discharges  into  the  chimney,  and  in  boiler  houses  with  high — 
and  low — pressure  lines,  two  main  dampers  ought  to  be  applied. 

As  we  have  learned  in  the  preceding  pages,  the  analysis  of  the 
flue-gases  gives  us  an  excellent  and  thoroughly  reliable  means  to 
ascertain  at  any  moment  how  many  pounds  or  tons  of  air  are 
used  in  burning  one  pound  or  ton  of  coal.  Therefore,  in  the  first 
days  of  the  campaign,  the  engineer,  together  with  an  experienced 
chemist,  has  to  control  the  work  in  the  boiler  house,  and,  above 
everything  else,  has  to  examine  the  regulation  of  the  air  necessary 
for  burning.  On  the  basis  of  several  analyses,  carefully  made, 
they  should  determine  in  what  position  of  the  main  and  of  the 
separate  dampers  the  combustion  gases  have  the  most  favorable 
composition,  that  is,  the  highest  percentage  of  carbon  dioxide 
without  any  carbon  monoxide.* 

*The  loss  caused  by  presence  of  carbon  monoxide  can  be  fig" 
ured  in  the  following  manner:  For  this  purpose  we  have  to  use 
the  thermal  equations:  CO  -f  O  =  CO-  -f-  67,q6o  calories  (i)  : 
C  -f-  O2  =  CO2  -f-  97,650  calories  (2).  These  equations  express 
that  in  burning  i  molecule  of  carbonic  oxid  to  carbonic  acid  67,960 
calories  are  produced,  and  in  burning  i  atom  of  carbon  to  carbonic 
acid  97,650  calories  are  generated.  Equation  (2)  we  can  represent 
in  two  phases  :  C  +  O  =  CO  +  x  calories  (a)  and  CO  -f  O  = 
002  +  67,960  calories  (b),  where  x  indicates  the  quantity  of 

23 


This  determined,  the  firemen  ought  to  be  instructed  to  act 
accordingly.  As  soon  as  the  firemen  are  accustomed  to  certain 
positions  of  the  dampers  they  will  find  it  to  be  unsuitable  to  shove 
the  damper  up  and  down  often,  and  they  will  do  so  only  in  case 
it  is  fully  expedient.  For  instance,  only  the  separate  damper  of 
any  boiler  ought  to  be  closed  while  its  grates  are  cleaned  from 
ashes  and  slag.  Or,  if  the  steam  pressure  in  all  the  boilers  rises 
too  high,  and  the  combustion  is  pretty  brisk,  then  it  is  advisable  to 
lower  the  main  damper,  etc.  It  is  necessary,  at  any  rate,  positively 
to  counteract  the  bad  practice  of  many  firemen  to  use  a  great 
surplus  of  air. 

Concerning  the  composition  of  the  coal — whether  bituminous 
(soft  coal)  or  brown  coal — I  would  say  it  is  profitable  to  buy 
a  coal  as  free  from  ash  as  possible.  If,  for  instance,  there  is  a 
choice  of  purchasing  a  coal  containing  either  5  per  cent  ash  for 
$4  a  ton — to  take  a  round  figure — or  a  coal  with  10  per  cent  ash 
for  $3.80  a  ton,  there  can  be  no  doubt  that  the  first  one  is  prefer- 
able. A  simple  consideration  shows  this. 

In  the  first  place  the  last  mentioned  coal  contains  5  per  cent 
more  ash,  which  means  5  per  cent  less  combustible  substance,  i.  e., 

5 
it  has  only  the  value  $4.00  —  4.00  X =  $3.80.     Besides,  as  a 

IOO 

coal  richer  in  ash,  it  requires  a  more  frequent  cleaning  of  the 


calories  which  I  atom  of  carbon  furnishes  in  burning  to  carbonic 
oxide.  Adding  (a)  and  (b),  we  have:  C  +  CO  +  O,=  CO  +  CO, 
+  67,960  calories  +  x  calories  (3).  Subtracting  equation  (2) 
from  equation  (3)  and  solving  the  resulting  equation,  we  find 
that  x  equals  29,690  calories.  So  that  I  atom  of  carbon,  or  12 
kilos,  of  carbon,  produce  29,690  calories  in  burning  to  carbonic 

29,690 
oxid,  hence  I  kilo  of  carbon  produces  -      —  =  2,474  calories.    On 

12 

the  other  hand  we  know  from  equation  (2)  that  12  kilos  of 
carbon  produce  97,650  calories  in  burning  to  carbonic  acid,  there- 

97,650 
fore  i  kilo  of  carbon  produces  -      —  =  8,137.5  calories.     Conse- 

12 

quently,  I  kilo,  of  carbon  would  lose  8,137.5 —  2,474  :=  5,663.5 
calories,  if  all  carbon  would  burn  to  carbonic  oxid,  and  for  each 

5,663.5 

i  per  cent  the  loss  equals  —          =  56.6  calories. 
100 

24 


grates,  consequently  more  work,  and  causes  the  cold  air  to  enter 
the  grates ;  furthermore,  a  part  of  the  heat  is  lost  by  the  hot  ashes 
falling  through  the  grates.  The  coal  must  be  of  medium  size 
and  accommodated  to  the  construction  of  the  grates.  Similarly, 
it  is  more  profitable  to  buy  dry  coal  for  a  correspondingly  higher 
price.  For,  apart  from  the  fact  that  the  real  value  of  the  coal 
is  decreased  by  the  weight  of  the  moisture,  a  part  of  the  avail- 
able heat  is  unproductively  used  for  the  evaporation  of  the  mois- 
ture. Since  the  heat  of  vaporization  of  water  equals  600  calories, 
every  per  cent  of  moisture  contained  in  a  coal  uses  unproductively 
six  calories  of  heat.  This  fact  is  important  for  factories  using 
brown  coal  as  fuel,  because  the  latter  is  generally  distinguished 
by  a  high  content  of  moisture.  Finally,  coal  should  be  procured 
that  is  as  free  from  sulphur  as  possible,  for  sulphur  burning  to 
sulphur-dioxide  corrodes  the  boiler  plates. 

As  for  the  feed  water,  its  temperature  must  be  very  uniform. 
If  there  is  not  sufficient  condensed  water  from  exhaust  steam,  the 
firemen  usually  supply  the  boilers  with  cold  water.  Apart  from 
the  fact  that  the  feeding,  sometimes  with  hot  water,  sometimes 
wfth  cold  water,  is  injurious  to  the  boilers,  causing  an  alternate 
expansion  and  contraction  which  may  cause  the  boilers  to  leak, 
the  formation  of  steam  takes  place  irregularly  under  these  condi- 
tions. In  order  to  prevent  this  defect,  a  heater  should  be  placed 
in  the  boiler  house,  heated  by.  exhaust  steam,  through  which  the 
feed  water  must  pass,  and  which,  by  means  of  inlet  and  outlet 
valves,  can  be  heated  to  the  temperature  desired  before  going 
into  the  suction  tank,  from  which  the  feed  pump  forces  the  water 
into  the  boilers. 

The  feed  water  should  have  as  high  temperature  as  possible. 
The  boilers  are  thereby  relieved  of  too  forcible  firing,  and,  on 
the  other  hand,  tensions  of  the  .boiler  plates  are  avoided.  If  there 
is  not  sufficient  exhaust  steam  in  the  factory  to  heat  the  feed 
water,  so  that  cold  water  must  be  used,  the  water  can  be  heated 
by  means  of  an  "economi/er,"  in  case  the  combustion  gases  in  the 
flue  are  sufficiently  hot,  and  the  draught  in  the  chimney  is  strong 
enough.  It  is  to  be  regretted  that  the  "economizer"  is  known 
and  used  by  very  few  factories.  This  appliance,  consisting  of  a 
system  of  pipes,  can  easily  be  placed  in  the  flue  about  200  milli- 
meters under  its  arch.  The  feed  water  forced  by  means  of  the 
pump  through  these  pipes  is  heated  by  the  combustion  gases  in  the 
flue  before  it  reaches  the  boilers.  Should  it  be  necessary  to 


remove  the  economizer  during  the  work,  one  needs  only  to  close 
its  valve  in  front  of  the  flue,  so  that  the  feed  water  is  forced 
directly  from  the  suction  tank  into  the  boilers. 

My  notes  in  a  sugar  factory  in  Germany,  having  a  daily  ca- 
pacity of  2,ico  centweights  of  beets,  show  that  the  temperature  of 
the  feed  water  by  such  an  economizer,  of  44  square  meters  sur- 
face and  1.32  cubic  meters  volume,  was  increased  about  40°  C. 
It  is  evident  that  the  hotter  the  gases  are  in  the  flue,  and  the 
slower  the  feed  pump  works,  the  more  the  feed  water  is  heated 
by  the  economizer. 

As  already  mentioned,  the  analyses  of  the  flue  gases  in  the 
high-pressure  boilers  show  a  more  favorable  composition  than 
those  in  the  low-pressure  boilers,  i.  e.,  the  fuel  is  utilized  in  the 
former  more  completely  than  in  the  latter.  Another  fact  speaks 
also  in  favor  of  the  high-steam  boilers.  Indeed,  let  us  consider 
the  following  table : 

Steam  of  I  aimos.  absol.  press,  has  100.0°  C.,  requires  622.0  cals. 
Steam  of  2  atmos.  absol.  press,  has  120.6°  C,  requires  628.3  cals. 
Steam  of  3  atmos.  absol.  press,  has  1.34.0°  C.,  requires  632.4  cals. 
Steam  of  5  atmos.  absol.  press,  has  152.2°  C.,  requires  637.9  cals. 
Steam  of  10  atmos.  absol.  press,  has  180.3°  C.,  requires  646.5  cals. 

This  table  shows  that : 

Steam  of  I  atmos.  absol.  press,  req.  622.0  cals.  for  each  atmos. 
Steam  of  2  atmos.  absol.  press,  req.  314.1  cals.  for  each  atmos. 
Steam  of  3  atmos.  absol.  press,  req.  210.8  cals.  for  each  atmos. 
Steam  of  5  atmos.  absol.  press,  req.  127.6  cals.  for  each  atmos. 
Steam  of  10  atmos.  absol.  press,  req.  64.6  cals.  for  each  atmos. 

We  thus  observe  that  the  higher  pressure  the  steam  has  the 
fewer  calories  or — what  is  the  same — the  less  coal  it  requires,  and, 
consequently,  the  cheaper  it  is. 

It  could  hardly  be  the  intention  of  the  writer  of  this  article 
to  fully  exhaust  so  important  a  question  as  fuel  economy  in  sugar 
factories,  because  it  is  not  practicable  in  the  limits  of  an  article 
in  a  journal.  For  instance,  the  question  of  the  losses  caused  by 
conduction  or  radiation*  of  heat  was  not  touched  upon  at  all.  By 


*These  losses  within  the  boiler  house  can  be  calculated  as  fol- 
lows :  By  means  of  the  thermal  equations  (C,  Oz)  =  97,650 
calories,  (H2,  O)  =68,460  calories  and  (S,  O*)  =  71,080  calories 
we  are  able  to  figure  the  total  quantity  of  heat  which,  say,  one 
ton  of  the  coal  can  furnish.  Subtracting  from  this  result  the 
easily  calculable  losses  occasioned  by  the  escaping  gases  and  hot 
ashes,  there  remains  the  available  heat  (a)  which  serves  really 

26 


this  article,  however,  it  was  intended  to  call  the  attention  of  the 
interested  circles  to  several  most  important  points  where  consider- 
able economy  of  fuel  can  be  attained.  From  the  data  mentioned 
here,  it  follows  that  a  factory  works  economically  in  the  boiler 
house,  if  the  following  conditions  are  fulfilled :  Correct  regula- 
tion of  air  necessary  for  combustion,  which  is  the  most  essential 
condition;  escaping  combustion  gases  of  low  temperature — the 
higher  the  chimney  the  lower  can  be  the  temperature  of  the  gases ; 
coal  as  free  from  ash,  slag  and  sulphur  as  possible,  to  which  the 
size  of  the  coal  and  the  construction  of  the  grate  must  be  care- 
fully adjusted;  feed  water  of  uniform  temperature  and  as  hot  as 
possible,  and.  finally,  steam  of  high  pressure  for  the  engines. 


for  the  heating  of  the  boilers.  Knowing  further  the  average 
temperature  and  the  quantity  of  feed  water  with  which  the  boilers 
are  supplied  as  well  as  the  temperature  to  which  the  water  in 
the  boilers  is  raised,  one  can  easily  determine  the  amount  of 
available  heat  (b)used  for  the  formation  of  steam  only.  Sub- 
tracting (b)  from  (a)  gives  rougly  the  loss  of  heat  through 
conduction  and  radiation. 


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